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Diffstat (limited to 'ext/B/NOTES')
| -rw-r--r-- | ext/B/NOTES | 168 |
1 files changed, 0 insertions, 168 deletions
diff --git a/ext/B/NOTES b/ext/B/NOTES deleted file mode 100644 index 89d03ba9a2..0000000000 --- a/ext/B/NOTES +++ /dev/null @@ -1,168 +0,0 @@ -C backend invocation - If there are any non-option arguments, they are taken to be - names of objects to be saved (probably doesn't work properly yet). - Without extra arguments, it saves the main program. - -ofilename Output to filename instead of STDOUT - -v Verbose (currently gives a few compilation statistics) - -- Force end of options - -uPackname Force apparently unused subs from package Packname to - be compiled. This allows programs to use eval "foo()" - even when sub foo is never seen to be used at compile - time. The down side is that any subs which really are - never used also have code generated. This option is - necessary, for example, if you have a signal handler - foo which you initialise with $SIG{BAR} = "foo". - A better fix, though, is just to change it to - $SIG{BAR} = \&foo. You can have multiple -u options. - -D Debug options (concat or separate flags like perl -D) - o OPs, prints each OP as it's processed - c COPs, prints COPs as processed (incl. file & line num) - A prints AV information on saving - C prints CV information on saving - M prints MAGIC information on saving - -f Force optimisations on or off one at a time. - cog Copy-on-grow: PVs declared and initialised statically - no-cog No copy-on-grow - -On Optimisation level (n = 0, 1, 2, ...). -O means -O1. - Currently, -O1 and higher set -fcog. - -Examples - perl -MO=C foo.pl > foo.c - perl cc_harness -o foo foo.c - - perl -MO=C,-v,-DcA bar.pl > /dev/null - -CC backend invocation - If there are any non-option arguments, they are taken to be names of - subs to be saved. Without extra arguments, it saves the main program. - -ofilename Output to filename instead of STDOUT - -- Force end of options - -uPackname Force apparently unused subs from package Packname to - be compiled. This allows programs to use eval "foo()" - even when sub foo is never seen to be used at compile - time. The down side is that any subs which really are - never used also have code generated. This option is - necessary, for example, if you have a signal handler - foo which you initialise with $SIG{BAR} = "foo". - A better fix, though, is just to change it to - $SIG{BAR} = \&foo. You can have multiple -u options. - -mModulename Instead of generating source for a runnable executable, - generate source for an XSUB module. The - boot_Modulename function (which DynaLoader can look - for) does the appropriate initialisation and runs the - main part of the Perl source that is being compiled. - -pn Generate code for perl patchlevel n (e.g. 3 or 4). - The default is to generate C code which will link - with the currently executing version of perl. - running the perl compiler. - -D Debug options (concat or separate flags like perl -D) - r Writes debugging output to STDERR just as it's about - to write to the program's runtime (otherwise writes - debugging info as comments in its C output). - O Outputs each OP as it's compiled - s Outputs the contents of the shadow stack at each OP - p Outputs the contents of the shadow pad of lexicals as - it's loaded for each sub or the main program. - q Outputs the name of each fake PP function in the queue - as it's about to processes. - l Output the filename and line number of each original - line of Perl code as it's processed (pp_nextstate). - t Outputs timing information of compilation stages - -f Force optimisations on or off one at a time. - [ - cog Copy-on-grow: PVs declared and initialised statically - no-cog No copy-on-grow - These two not in CC yet. - ] - freetmps-each-bblock Delays FREETMPS from the end of each - statement to the end of the each basic - block. - freetmps-each-loop Delays FREETMPS from the end of each - statement to the end of the group of - basic blocks forming a loop. At most - one of the freetmps-each-* options can - be used. - omit-taint Omits generating code for handling - perl's tainting mechanism. - -On Optimisation level (n = 0, 1, 2, ...). -O means -O1. - Currently, -O1 sets -ffreetmps-each-bblock and -O2 - sets -ffreetmps-each-loop. - -Example - perl -MO=CC,-O2,-ofoo.c foo.pl - perl cc_harness -o foo foo.c - - perl -MO=CC,-mFoo,-oFoo.c Foo.pm - perl cc_harness -shared -c -o Foo.so Foo.c - - -Bytecode backend invocation - - If there are any non-option arguments, they are taken to be - names of objects to be saved (probably doesn't work properly yet). - Without extra arguments, it saves the main program. - -ofilename Output to filename instead of STDOUT. - -- Force end of options. - -f Force optimisations on or off one at a time. - Each can be preceded by no- to turn the option off. - compress-nullops - Only fills in the necessary fields of ops which have - been optimised away by perl's internal compiler. - omit-sequence-numbers - Leaves out code to fill in the op_seq field of all ops - which is only used by perl's internal compiler. - bypass-nullops - If op->op_next ever points to a NULLOP, replaces the - op_next field with the first non-NULLOP in the path - of execution. - strip-syntax-tree - Leaves out code to fill in the pointers which link the - internal syntax tree together. They're not needed at - run-time but leaving them out will make it impossible - to recompile or disassemble the resulting program. - It will also stop "goto label" statements from working. - -On Optimisation level (n = 0, 1, 2, ...). -O means -O1. - -O1 sets -fcompress-nullops -fomit-sequence numbers. - -O6 adds -fstrip-syntax-tree. - -D Debug options (concat or separate flags like perl -D) - o OPs, prints each OP as it's processed. - b print debugging information about bytecompiler progress - a tells the assembler to include source assembler lines - in its output as bytecode comments. - C prints each CV taken from the final symbol tree walk. - -S Output assembler source rather than piping it - through the assembler and outputting bytecode. - -m Compile as a module rather than a standalone program. - Currently this just means that the bytecodes for - initialising main_start, main_root and curpad are - omitted. - -Example - perl -MO=Bytecode,-O6,-o,foo.plc foo.pl - - perl -MO=Bytecode,-S foo.pl > foo.S - assemble foo.S > foo.plc - byteperl foo.plc - - perl -MO=Bytecode,-m,-oFoo.pmc Foo.pm - -Backends for debugging - perl -MO=Terse,exec foo.pl - perl -MO=Debug bar.pl - -O module - Used with "perl -MO=Backend,foo,bar prog.pl" to invoke the backend - B::Backend with options foo and bar. O invokes the sub - B::Backend::compile() with arguments foo and bar at BEGIN time. - That compile() sub must do any inital argument processing replied. - If unsuccessful, it should return a string which O arranges to be - printed as an error message followed by a clean error exit. In the - normal case where any option processing in compile() is successful, - it should return a sub ref (usually a closure) to perform the - actual compilation. When O regains control, it ensures that the - "-c" option is forced (so that the program being compiled doesn't - end up running) and registers a CHECK block to call back the sub ref - returned from the backend's compile(). Perl then continues by - parsing prog.pl (just as it would with "perl -c prog.pl") and after - doing so, assuming there are no parse-time errors, the CHECK block - of O gets called and the actual backend compilation happens. Phew. |